The present invention relates to a pressure sensitive transferring adhesive tape which is prepared by forming an adhesive agent layer on a substrate tape.
As a kind of double-sided adhesive tape, a non supported double-sided adhesive tape that does not have a supporter (core material) and transfers adhesive agent layer alone to an adherent is well-known and is widely used in various fields as a pressure sensitive transferring adhesive tape. The conventional structural feature of said pressure sensitive transferring adhesive tape is illustrated as follows. That is, an adhesive agent layer is formed on one surface of a releasable liner or a releasable substrate and is wound like a roll. Recently a transferring device characterizing by attaching these small wound type tape roll to a transferring tool is developed and is on the market for the office supplies uses under the name of xe2x80x9ctape adhesivexe2x80x9d.
The transferring device is consisted of;
a feeding reel to which a pressure sensitive transferring adhesive tape is wound;
a transferring head that transfers the adhesive agent layer of the pressure sensitive transferring adhesive tape provided from the feeding reel to an adherent by releasing from the substrate;
and a winding up reel to wind up the used substrate after transferring.
These are arranged in a case that can be handled by one hand.
The transferring device is illustrated by FIG. 1. In FIG. 1, a feeding reel 2 which winds and stores the pressure sensitive transferring adhesive tape 5 in a roll state, and a winding up reel 3 which winds up and stores the used substrate after transferring are arranged in a case 1. Said case 1 is a main body of the pressure sensitive transferring device that can be handled by one hand, and is to expose a part of the pressure sensitive transferring adhesive tape from the end point of the case so as the transferring head 4, which transfers the adhesive agent layer to the adherent by releasing it from the substrate, to contact to the adherent.
When said pressure sensitive transferring adhesive tape is used for the adhering means of paper, it displays following strong points compared with the conventional liquid type adhesives or solid type adhesives. Namely, adhesive agent can be easily transferred to the surface of the adherent without making the hands of operator sticky, the drying up time to complete the adhering process is not needed, and the paper, which is the adherent, is not wrinkled. Further, after the necessary length of adhesive tape is transferred to the surface of the adherent, the adhesive agent layer can be cut easily by lifting the transferring device vertically from the surface of the adherent or by moving it to the horizontal direction. Therefore, compared with the conventional double-sided adhesive tape with supporter, it is not necessary to cut the tape previously to the necessary length, and since the releasable substrate from which the adhesive agent layer is released is wound up to the winding up reel, there is no waste at the actual use. That is, it can be said as a very convenient adhesive goods.
However, since the adhesive agent of adhesive agent layer is coated continuously on the surface of releasable substrate, the adhesive agent causes stringiness and stretching problem at the cutting action and cannot be cut smoothly, which is recognized as the problem so called poor adhesive severability.
To avoid the problem, the methods to make the adhesive agent layer form fine dotted shape or to arrange the adhesive agent layer so as to form block shape keeping a distance between blocks are proposed, however, these proposed methods have a problem that the adhering strength becomes weaker in comparison with that of the continuous coating method.
The inventors of this invention have conduced a intensive study to dissolve the above mentioned problem and accomplished the present invention, and the object of the present invention is to provide a pressure sensitive transferring adhesive tape which has the excellent adhesive severability maintaining the sufficient adhering strength.
The above mentioned object can be accomplished by a pressure sensitive transferring adhesive tape, comprising a substrate on which surface an adhesive agent layer is provided, said adhesive agent layer is characterized to be coated over the surface of the substrate so as to form discontinuous island shape pattern, and the surface area of said one island is from 1 to 100 mm2, further the distance between adjacent islands is from 0.1 to 4 mm.
Further, said object can also be accomplished by a pressure sensitive transferring adhesive tape, comprising a substrate on which surface an adhesive agent layer is provided, the surface of said adhesive agent layer is characterized to have concave and convex shape, and the thickness of concave part is thinner than 80% of the thickness of convex part, further the gel fraction of said adhesive agent layer is bigger than 15% by weight.
Furthermore, it is desirable that the viscosity at 25xc2x0 C. of adhesive agent composition at the coating process is from 0.1 to 50 Paxc2x7S, and the content of involatile component in said adhesive agent composition is from 10 to 80%.